The study of metal ions in biochemical systems encompasses two significant aspects of enzyme reactions. First, the metalloenzymes and metal activated enzymes that require the presence of the metal in order for the enzyme to carry out its function and second, the enzyme systems which are disrupted or inhibited by the presence of certain metal ions (primarily the heavy metals). This study proposes to use the native fluorescence of the amino in enzymes to gather information about these two aspects of enzyme reactions. This means that no external probe will have to be added which may perturb the enzyme or disrupt the effect of the metal. The other method used in this study is halide ion NMR. This technique can be used to detect binding of the metal ion and to determine the accessibility to and local motion at the binding site. If successful, the techniques developed in this study will help to design new drugs for the treatment of heavy metal poisoning and would provide fundamental information about the role of the metal ion in metalloenzymes and metal activated biochemical systems.